This invention relates to a self-adjusting clutch, and more specifically, to a sensor assembly adapted to absorb vibrational forces and prevent misadjustment of the clutch.
Clutches are utilized in many vehicle drive applications to selectively transmit or break a drive connection between an engine and a transmission. In one common type of clutch that is widely utilized in heavy vehicles, a clutch includes a pressure plate that rotates with a clutch cover. Levers selectively force the pressure plate against a member that is to be driven to rotate with the pressure plate and clutch cover. When the pressure plate is forced against the driven member, it sometimes must move to accommodate wear on friction surfaces in the clutch. Wear adjustment is typically achieved by using a wear sensor assembly that senses the wear within the clutch. The wear sensor assembly cooperates with an adjustment assembly, such as mating adjusting rings, to adjust the location of the clutch components relative to one another to maintain pedal travel parameters and desired operation of the clutch.
In one very standard way of sensing wear, a pin and bushing arrangement cooperate with one another to adjust the position of the pressure plate relative to the cover in response to an adjustment force. However, vibrational forces may cause the pin and bushing to adjust the position of the pressure plate when adjustment is not needed or prevent proper adjustment. For example, a collision between the trailer and cargo dock may transmit a vibration through the pressure plate that may undesirably adjust the clutch. As a result, the clutch becomes misadjusted and may cause undesirable clutch operation. Therefore, what is needed is a sensor assembly that discriminates between adjustment forces and vibrational forces to prevent misadjustment of the clutch caused by vibrational forces.
The present invention provides a clutch comprising a clutch cover assembly including a cover rotatable about and axis. The pressure plate is spaced apart from the clutch cover assembly and is moveable along the axis for engaging the clutch member. A sleeve including a retainer is moveable along the axis between engaged and disengaged positions. A lever having first and second opposing ends are respectively supported between the container and the clutch cover assembly. The lever includes a fulcrum arranged between first and second ends supported by a portion of the pressure plate. The present invention utilizes a resilient member arranged between the portion of the pressure plate and the fulcrum for absorbing vibrational forces transmitted in the direction of the axis.
Accordingly, the above invention provides a sensor assembly that discriminates between adjustment forces and vibrational forces to prevent misadjustment of the clutch caused by vibrational forces.